Almost everyday when I check Flightaware, it shows big delays at SFO usually due to low clouds or runway in use. How come there are hardly ever any delays at OAK or SJC when they are getting basically the same weather? Now I know that the volume at SFO is much greater, but they do have 4 runways to operate on. OAK only has 1 commercial runway (they do have shorter general aviation runways as well) and SJC has 2 commercial runways. Do the close proximity of the parallel runways at SFO prohibit smooth ops when the low clods come in? It just seems that OAK and SJC can handle these problems with better efficiency than SFO.

When weather hits SFO, they go down to 1 arrival runway (from the normal of 2), whereas OAK and SJC are ALWAYS 1-arrival runway. So adverse weather does not materially impact them. Their traffic can be handled by 1-runway without delays, so there is almost never a reason for them to have ground delays.

Also, those three airports do NOT have the same weather. SJC almost never gets low clouds/fog, and OAK far less than SFO also. While this is not the primary reason (per my explanation above), it's worth noting how variable the weather is even within a couple of miles in the bay area.

Quoting dartland (Reply 1):When weather hits SFO, they go down to 1 arrival runway (from the normal of 2), whereas OAK and SJC are ALWAYS 1-arrival runway. So adverse weather does not materially impact them. Their traffic can be handled by 1-runway without delays, so there is almost never a reason for them to have ground delays.

Also, those three airports do NOT have the same weather. SJC almost never gets low clouds/fog, and OAK far less than SFO also. While this is not the primary reason (per my explanation above), it's worth noting how variable the weather is even within a couple of miles in the bay area.

Also, OAK and SJC doesn't have nearly the traffic volume as SJC or OAK. SFO, I'm sure, has more traffic than OAK and SJC combined.

SFO runways are too close together to meet FAA requirements for parallel IFR landings. Having just one runway for landing pretty much paralyzes them.

You basically said it all right there. SFO has a lot more traffic than either OAK or SJC, especially since both AA and UA pulled out of OAK recently, and with VX setting up shop at SFO. Why SFO is such a problem is, like many of the airports out on the east coast (LGA comes quickly to mind), the airlines build flight schedules that are good for a good weather day. But in the winter time, the airport is very prone to fog, and this causes many problems. SFO operates most efficiently with good visibility which allows the airport to run visual approaches to the 28's, which is necessary because ATC needs the planes to maintain visual separation with the runways so close together. Sometimes in less than ideal conditions, they can run what is called SOIA (which I believe stands for Staggered Outer Inner Approaches), which although not ideal, they can put more planes down by alternating the landing runway. However in a full IFR day where they have to run ILS approaches, they get down to one arrival runway, which usually ends up being a 30 AAR (Aircraft Acceptance Rate) which is half of the normal 60. With demand per hour far exceeding 30 airplanes, delays happen.

I don't have the stats for OAK or SJC. However, as you said at OAKGA is separate from the commercial traffic, meaning that 11-29 drives the operation at OAK, and given the flight schedule, they probably have fewer than 30 commercial arrivals per hour at OAK. SJC has two parallel runways, so they can run a slightly higher arrival rate than 30 (probably between 32 and 36) because the arrival runway is not conflicting with any departing traffic the way it does at both SFO and OAK.

But you do raise an interesting point. With BART servicing OAK as well as SFO, and with OAK being geographically closer to San Francisco than SFO, and with no delay problems, why can't OAK attract more traffic? If i was a business traveller, and my time was critical, to me its no decision, unless the weather is perfect, OAK will always get me to the Bay Area quicker than SFO.

Quoting dartland (Reply 1):it's worth noting how variable the weather is even within a couple of miles in the bay area.

This can't be overstated. Driving south on 101 from San Francisco down the peninsula can feel like driving from a freezer into an oven temperature wise, as well as moving from a dark room into the bright sunshine. The topography of the hills that run down the spine of the peninsula really effects where and how the fog and moisture can roll into the area, and the most southern point from San Francisco for noticeable and drastic weather variations tends to be a mile or so south of SFO. I'll go as far as saying most of the time when SFO is experiencing weather, SJC isn't.

I guess my next question would be, with such a delay prone airport such as SFO, do the "pros" outweigh the "cons" when it comes to an airline operating a hub from there? I imagine with all the delays, the airlines are cutting into their bottom line, which we all know, is really what matters. Didnt WN pull out of SFO years back because of all the delays? I know they are back now, but for how long? Will the delays get them to drop SFO again? I guess my question could be aimed at most of the delay prone airports such as EWR, LGA, ORD, etc. When does too many delays actually start hurting them financially?

Quoting apodino (Reply 4):But in the winter time, the airport is very prone to fog,

Actually, fog is a problem all-year, especially in the summer. Winter we get rain, summer has more fog.

Quoting apodino (Reply 4):But you do raise an interesting point. With BART servicing OAK as well as SFO, and with OAK being geographically closer to San Francisco than SFO, and with no delay problems, why can't OAK attract more traffic? If i was a business traveller, and my time was critical, to me its no decision, unless the weather is perfect, OAK will always get me to the Bay Area quicker than SFO.

SFO is easier than OAK from the city for two reasons:
a) BART service runs to both, but at SFO it puts you right in the terminal. At OAK, you have to take a bus shuttle which is annoying.
b) While traffic can be bad to either -- the Bay Bridge is a huge problem for driving, as is the Nimitz Freeway (I-880) connecting the Bay Bridge down past Port of Oakland, to the airport. Those are two of the most delay-prone highways in the area. While US-101 to SFO is often not great, it's definitely the lesser evil.

OAK definitely has its advantages, especially for short-haul morning flying where traffic might be low and SFO is fogged in, but overall SFO is still the go-to.

Yes WN pulled out back in March of 2001 citing multiple factors, most importantly the delays. They came back in 2007. Considering that WN's strategy now includes serving airports like EWR, LGA, DCA, which are even more delay-prone, I don't see them exiting SFO again.

Quoting apodino (Reply 4):SFO has a lot more traffic than either OAK or SJC, especially since both AA and UA pulled out of OAK recently, and with VX setting up shop at SFO

Exactly, the last couple years passenger traffic and total movements at SFO have skyrocketed. In 2011, SFO handled 41 million passengers on over 400,000 operations, far higher than OAK: 9.2 million with 215,000 ops. and SJC: 8.3 million with 120,000 ops.

Then combine the traffic with our wonderful natural air conditioner and runway separation, and there you have it...

Quoting dartland (Reply 1):it's worth noting how variable the weather is even within a couple of miles in the bay area.

Very true. I am not exaggerating when I tell you that I have found myself standing in cold, grey fog downtown. I walk two blocks south and suddenly I am standing in bright, warm sun. I turn around and there is a massive wall of fog hanging there.

Similarly, the south/east end of SFO (the airport itself) can be in bright sun and the north/west end can be in pea-soup fog.

It is my understanding that the issue is that 28L is 50 feet too close to 28R to allow for tandem IFR approaches. The FAA won't grant a waiver.

Agreed. When I was a kid growing up near SJC, we'd go up to SF when friends would visit from out of town. They would be confused when we'd be loading the trunk with sweatshirts while it was 85 and sunny. When we'd get to SF, they would understand why we brought the sweatshirts.

Quoting apodino (Reply 4):With BART servicing OAK as well as SFO, and with OAK being geographically closer to San Francisco than SFO, and with no delay problems, why can't OAK attract more traffic? If i was a business traveller, and my time was critical, to me its no decision, unless the weather is perfect, OAK will always get me to the Bay Area quicker than SFO.

OAK is ~20 miles to downtown San Francisco. SFO is 13 miles to downtown.

Someone else mentioned the hellish traffic on the Nimitz and the Bay Bridge. It's taken me three hours to go from the financial district in San Francisco to Hegenberger Rd before.

When going to San Francisco the scenery from the upper deck is just fantastic. One of the best views in the country.

"The coldest winter of my life was a summer in San Francisco." -Mark Twain. The reason SFO is fogged in is the sea breeze that sucks the fog in from the Pacific through the gap between the mountains and San Bruno. The warmer SJC is, the more rising air you get, thus a stronger sea breeze and more fog at SFO. IIRC, SJC only has one ILS, but when it gets bad there they can just switch to departure/arrival mode and not lose much throughput, not that it matters because the volumes are not that high.

Quoting IAHFLYR (Reply 15):Never heard it phrased like that before, I kind of like it! Now explain it.

Not sure if my terminology is correct, but at an airport like LAX, the instrument landing system can be used to land aircraft on parallel runways. They are spaced far enough apart that the aircraft don't need to be able to see each-other to avoid a collision or wake interference.

At SFO the runways are 50 feet too close together to allow for legal use of the instrument landing system if two aircraft are landing side-by-side, so if there are clouds below minimums, there will be at least some part of the approach in which the aircraft will not be able to see each-other and so they cannot maintain visual separation.

Quoting DocLightning (Reply 16):Not sure if my terminology is correct, but at an airport like LAX, the instrument landing system can be used to land aircraft on parallel runways

Maybe not the correct terminology but I still like it!

You're thinking of simultaneous independent approaches and there are a few different set of standards for the distance between centerlines to operate in that fashion. LAX for example would have 4,300' or more between centerlines and is able to conduct fully instrument approaches, duals that are side by side while IAH, DFW, DEN, and a few more can conduct triple approaches side by side by side as their three parallel runway centerlines are separated by at least 5,000'. ATL has a waiver from the 5,000' centerline standard and has a high update monitor RADAR to conduct triple approaches.

But SFO is no where near having enough distance between the runways to have airplanes side by side unless they are maintaining visual separation from the turn on point to the runway.

Quoting DocLightning (Reply 16):Not sure if my terminology is correct, but at an airport like LAX, the instrument landing system can be used to land aircraft on parallel runways. They are spaced far enough apart that the aircraft don't need to be able to see each-other to avoid a collision or wake interference.

At LAX, they can do simultaneous instrument landings to one runway on each side of the airport. So one of the 24s and one of the 25s. They can't do them to 24R and L (745 foot centerline spacing), or 25R and L (800 foot centerline spacing).

Quoting DocLightning (Reply 16):At SFO the runways are 50 feet too close together to allow for legal use of the instrument landing system if two aircraft are landing side-by-side, so if there are clouds below minimums, there will be at least some part of the approach in which the aircraft will not be able to see each-other and so they cannot maintain visual separation.

I don't think 800 foot centerline spacing gives you this ability, which is what SFO would have if they seperated the runways by an additional 50 feet. For side-by-side approaches, 4300 feet is the number that rings a bell.

Quoting vikkyvik (Reply 18):I don't think 800 foot centerline spacing gives you this ability, which is what SFO would have if they seperated the runways by an additional 50 feet. For side-by-side approaches, 4300 feet is the number that rings a bell.

So, basically, 28R would have to be moved all the way out to the end of the 1/19's. Ouch.

All of this explains why I will go several hundred miles out of my way to do connections at LAX instead of SFO. I'd use SJC or OAK if they had the connections I wanted. I only use SFO if that is my destination and I am not on a tight schedule. If I'm heading to SF for a same day meeting I usually fly to OAK and take BART or a very expensive taxi. I never depend on anything from RNO to SFO to be on time.

I broke that rule last spring intending to fly RNO-SFO-EWR. To my complete astonishment everything at SFO was on time that day. To make up for that the A320 went tech at the gate in Reno. I ended up hours late, missed the connection, ended up losing my first class set for a middle seat on a redeye in row 273, or something like that.

Quoting aklrno (Reply 21):
All of this explains why I will go several hundred miles out of my way to do connections at LAX instead of SFO. I'd use SJC or OAK if they had the connections I wanted. I only use SFO if that is my destination and I am not on a tight schedule. If I'm heading to SF for a same day meeting I usually fly to OAK and take BART or a very expensive taxi. I never depend on anything from RNO to SFO to be on time.

Same for me. I live in SF, but if there is a way to get where I'm going from OAK, I'll do it that way. I hate three-hour delays.

Quoting Kaiarahi (Reply 23):I guess I must be the odd one out. I fly regularly to AKL through SFO (because I detest international transit at LAX) and I've never had a WX delay. Hope I haven't just jinxed myself!

From AKL you might not. The fog at SFO tends to occur on a schedule, better at mid-day and worse in the AM and PM. AKL arrives mid-day. Also, a flight from AKL that departs 12 hours previously is not going to get a ground delay most likely because the precise weather at SFO can't be predicted 12 hours in advance. They can't make a flight from AKL circle for three hours, so the flight probably gets priority.

Flights from Southern California are delayed all the time. I once experienced a WX delay so long flying SBA-SFO that I literally could have dead-headed a rental car and arrived prior to the plane had I known in advance the delay would be so long.

It's a big problem at SFO and there doesn't seem to be a good solution any time in the near future.

SFO is a great airport as long as your flights are on-time. Transferring between terminals is effortless, the AirTrain is very useful and well-designed, the terminals are relatively new and/or refurbished, and there are a lot of destinations that can be reached non-stop (unfortunately, UA has most of the market). But the delays are really bothersome.

Quoting apodino (Reply 4):Sometimes in less than ideal conditions, they can run what is called SOIA (which I believe stands for Staggered Outer Inner Approaches)

Simultaneous Offset Instrument Approaches. IIRC, tt's a form of PRM approach: you have a No Transgression Zone (NTZ) the same size as you would for an ILS PRM approach (I don't know offhand how wide it is, but 2,000 feet rings a bell for some reason), and then where the approaches converge to the point where you can't maintain the NTZ anymore, the instrument portion ends, the trailing aircraft (28R) has to see the leading aircraft (28L), and the approach continues visually from there. There's a final monitor controller and everything just like a PRM approach. Because of the requirement for one airplane to see the other, the weather minimums are significantly higher than would be possible with an ILS PRM.

Quoting DocLightning (Reply 11):It is my understanding that the issue is that 28L is 50 feet too close to 28R to allow for tandem IFR approaches. The FAA won't grant a waiver.

Definitely not for simultaneous approaches, which require 4,300 feet separation (3,400 feet with a PRM approach). With 2,500 feet separation I believe you can do staggered approaches, where both approaches are in use and normal separation is maintained between aircraft on different approaches (i.e. the leading aircraft on 28L would be a least three miles from the next aircraft on 28R, which would be at least three miles from the next aircraft on 28L, etc.).

Quoting IAHFLYR (Reply 17):LAX for example would have 4,300' or more between centerlines and is able to conduct fully instrument approaches, duals that are side by side

Just to clarify, this is between runways that are on the north and south sides of the airport. LAX can't do instrument approaches to 24L and 24R simultaneously, or 25L and 25R. 25L and 24R on the other hand work fine.

Quoting Mir (Reply 26):Just to clarify, this is between runways that are on the north and south sides of the airport. LAX can't do instrument approaches to 24L and 24R simultaneously, or 25L and 25R. 25L and 24R on the other hand work fine.

Saying that BART services OAK is a bit misleading. You ride BART part of the way, get off, buy another ticket, and ride a bus over to OAK. The rail link to OAK is under construction, but even when completed you will have to change trains as the leg from the main BART line to OAK will not be connected to the BART system physically, i.e. a train cannot go from OAK to Emeryville.

Quoting Mir (Reply 26):
Simultaneous Offset Instrument Approaches. IIRC, tt's a form of PRM approach: you have a No Transgression Zone (NTZ) the same size as you would for an ILS PRM approach (I don't know offhand how wide it is, but 2,000 feet rings a bell for some reason), and then where the approaches converge to the point where you can't maintain the NTZ anymore, the instrument portion ends, the trailing aircraft (28R) has to see the leading aircraft (28L), and the approach continues visually from there. There's a final monitor controller and everything just like a PRM approach. Because of the requirement for one airplane to see the other, the weather minimums are significantly higher than would be possible with an ILS PRM.

Thanks for the explanation. My carrier doesn't fly into SFO at all but I hear it talked about on ATC telcons...and I always wondered how that whole SOIA thing worked.

Quoting DocLightning (Reply 24):From AKL you might not. The fog at SFO tends to occur on a schedule, better at mid-day and worse in the AM and PM. AKL arrives mid-day. Also, a flight from AKL that departs 12 hours previously is not going to get a ground delay most likely because the precise weather at SFO can't be predicted 12 hours in advance. They can't make a flight from AKL circle for three hours, so the flight probably gets priority.

What's the Alternate for inbound international flights like that if they can't land at SFO? I'm guessing SMF and FAT? I have seen quite a few UA heavies at SJC during a bad windstorm at SFO back in 2002.

Quoting BoeingGuy (Reply 34):What's the Alternate for inbound international flights like that if they can't land at SFO?

Typically OAK is the primary alternate for SFO. Depending on type, they may also go to SJC. And, there's even NUQ as a potential alternate. I remember as a kid seeing a few commercial aircraft at Moffett Field in the late '70s/early '80s that used it as an alternate. There's still California Air Guard C-130s and Volga-Dnepr An-124s using it regularly, so NUQ can handle them Big and Heavy!

Unless there is a region-wide event in the Bay Area such as a fire or earthquake, I doubt you'll see a deviation out of the Bay Area to as far a location as SMF or FAT. After that, you'll likely see alternates used based on the nature of the event and where the inbound aircraft is along its flight path when they learn that their primary destination is unavailable.

Quoting SJCflyer (Reply 35):Unless there is a region-wide event in the Bay Area such as a fire or earthquake, I doubt you'll see a deviation out of the Bay Area to as far a location as SMF or FAT.

AA has used SMF and FAT as alternates for SJC, at least back when SJC's ILS was only Cat 1. I remember a flight attendant telling me they deverted into FAT on a DFW-SJCMD-80 flight.

Likewise, I went out of SJC on the NRT 777 flight around 2000. My inbound ASMD-80 was in a holding pattern over Pt. Reyes until the fog lifted at SJC. The OGG-SJC and HNL-SJCAA 757s went to SMF and sat there until about noon before coming back to SJC (with a 6am scheduled arrivals!). The inbound NRT-SJC flight was very close to going to SMF but the fog lifted and they could land at SJC just before reaching that point in fuel.

Quoting apodino (Reply 4):With BART servicing OAK as well as SFO, and with OAK being geographically closer to San Francisco than SFO, and with no delay problems, why can't OAK attract more traffic?

Also, the terminal at OAK is small. The site map says "Terminal 1" and "Terminal 2" but they are both one building and a total of about 25 gates. T-2 is all WN, IIRC. Plus, as pointed out before, to get to BART, you need to take a bus to Coliseum station. I don't think that requires a separate ticket, but it is still an inconvenience. I live in STS and, when I fly, I go through OAK. Cheaper parking, better traffic, and lower fares.

Also, living in the North Bay, we have much more sun than SFO. Even in winter. There are summer days when we are basking in the sunshine all day, but there are 1 to 2 hour delays at SFO but OAK is on time. It is the microclimates here.

Hardly. It's not difficult, but any international hub airport in 2012 where you can't connect between all terminals inside the secure area is automatically disqualified from being an "effortless" transit.

The fact I can't transit from T2 to T1 inside security, like I did last night, absolutely boggles the mind.

LAX, for the same reasons (among others), is also disqualified.

In fact, there are really only a few hubs that earn the "effortless" moniker. DFW, ATL (*gags*), DEN, IAD.

Interestingly, all of those airports are pretty spread out, which means they can require a lengthy walk. So "effortless" is a bit of a misnomer anyway.